1. Technical Field of the Disclosure
The present embodiment is related in general to chucks for use in connection with pumps for inflating bicycle tires or other inflatable objects, and in particular to a pump chuck that easily connects to a valve stem of a tire valve to produce an air tight seal.
2. Description of the Related Art
It is well known that for inflating the tires of vehicles, particularly two-wheel vehicles such as bicycles, motorcycles, or motor-assisted cycles, a flexible connector is generally used having one end coupled and sealed to a source of air under pressure such as a bicycle pump or hand air pump, the other end is sealed onto the valve stem of the tire valve. Tire inflation devices typically have a chuck for attaching to and substantially sealing at the valve stem of the tire valve (or other inflatable article). In order to properly inflate the article, the chuck must seal at the valve and limit or preclude leakage of air at the chuck-valve connection. Often, such a seal is not readily made with conventional chucks and leakage occurs, often leading to improperly inflated tires or articles.
Conventional chucks on bicycle tire pumps are difficult to use as they use a cam and lever to compress a rubber seal against the valve stem. The rubber seal must prevent air leaks at pressures up to 125 PSI as well as retain the chuck on the stem at pressures up to 125 PSI. This requires a significant lever force to compress the rubber seal making it hard to attach the chuck to the valve stem. Further, it is difficult to insert the chuck on to the valve stem due to tight seal clearance and it is difficult to actuate the cam lever due to the large force required to compress the seal on to the valve stem. Moreover, it is also difficult to hold the stem tightly to insert the chuck on to the valve stem when tire is flat or has little air.
Recent advancements in the art disclose a chuck for connecting a pressure device to a valve stem of a pressurized vessel including a body portion having a first passageway that is configured to receive an outer tube portion of a valve stem of a pressurized vessel therein. The body portion has a guide portion at an inner end of the first passageway. A pin element is movably disposed within a second passageway of the body portion and is movable along the coaxial passageways. The guide portion includes an alignment element at least partially around the second passageway and extending longitudinally toward an engaging end of the body portion and at least partially around the pin element for engaging and supporting an interior portion of the end of the outer tube portion of the valve stem. However, external pressure has to be applied to form an air tight seal.
One of the existing pump chucks comprises a main body defining a chamber and having a top end and a bottom end; a force transmitting member positioned in the chamber adjacent to the top end of the main body; a resilient collar positioned in the chamber adjacent to the bottom end of the main body and in engagement with the force transmitting member; and a camming device mounted at the top end of the main body. The collar defines an axial cavity having an inner wall and an inside diameter. Compression of the collar decreases the inner diameter of the collar, and thus causes the collar to engage and seal the valve stem positioned in the axial cavity. However, the user will have to exert significant force to compress the collar to engage and seal the valve stem.
Another existing device discloses an air chuck that provides a manual press-fitted connection to the valve stem of an automobile tire or the like, consisting of a tubular body member attachable to the hose end and having a pressure-seated plunger valve therein. The plunger valve has a plunger extension which, when pressed over the valve stem of an automobile tire, opens both the plunger valve and the air valve of the stem to admit air to the stem. The invention is characterized by the construction of the body member, hose and plunger valve assembly, wherein a single assembly member performs the functions of providing a sealed connection of the hose to the body member, limiting and controlling the motion of the plunger valve, and providing for air passage from the hose to the plunger valve. However, the connection has to be made manually by pressing the plunger.
Various other pump chucks exist that are used in tire inflating devices. One such device includes an air chuck for tire valves having a plurality of teeth which positively lock the chuck to the valve stem by a plurality of closely spaced, radially inwardly projecting fingers which are moved into engagement with the valve stem by sliding a sleeve member over the fingers. The chuck includes a means for depressing the tire valve pin and a means for sealing the outer end of the valve when the chuck is engaged. Another device includes a quick-coupling connector that comprises a tubular body with a piston actuator which may be formed in one or two parts between an operating lever and a sealing ring which in response to the displacement is compressed and tightly squeezed against the inflation valve conforming to its threaded outer surface and forming an air-tight connection. However, such devices require significant lever force to compress the rubber around the valve stem.
Based on the foregoing there is a demonstrable need for a pump chuck that easily attaches to the valve stem of a tire valve. Such a needed pump chuck would comprise a pivot clip that easily secures the valve stem in the pump chuck. Further, the pump chuck would be easy to hold over the valve stem when the tire is flat. Finally, the fastening device would be economical and reliable to use. The present invention overcomes prior art shortcomings by accomplishing these critical objectives.